Improvement in plates for artificial teeth



UNITED STATES PATENT QFFICE.

GEORGE MORRISON, OF PALMYRA, WISCONSIN.

IMPROVEMENT IN PLATES FOR ARTIFICIAL TEETH.

Specification forming part of Letters Patent No. 121,802, dated December 12, 1871.

To all 'whom it may concern:

Be it known that I, GEORGE MORRISON, of Palmyra, in Jefferson county and State of Wiscousin, have invented a new and useful Improvement in Plates for Artificial Teeth; and that the following is a full, clear, and exact description of the same', reference being had to the annexed drawing making a part of this specification, in Which- Figure l is a plan view on the top. Fig. 2 is a cross-sectional view of the same on the line w.

One of the greatest difficulties and annoyances experienced by persons who are obliged to wear artificial teeth, especially the upper set, is that the plates are constantly dropping down on account of the air from without nding ing re s s tween the plate and the roof of the mouth. There is an air-chamber, usually, made in the rootl of the plate. This air-chamber is the best means employed to hold suction plates in their places by means of exhausting the air therefrom, which causes a vacuum between the roof of the mouth and the plate, so that the pressure of air on the plate holds it firm in place; but, however, it is well known that the vacuiun cavity acts Well at first, but gradually draws the mucous mem brane or gum into it, and finally iills it by a more or less permanent enlargement or morbid growth of iiesh, which causesit to relax its pressure to the roof of the mouth, and finally will drop entirely down and fall out.

My invention consists in a device expressly for the purpose of obviating this difficulty by so constructing the cap A, which partly covers the air-chamber C as to prevent the membrane from llin g the ai r-chamber. This cap being two-fourths of a circle covers one-half ot the air-chamber, and by turning it One-fourth around changes the suction surface. It will be readily seen that the cap must be of great service to prevent the membrane or gum from tilling the air-chamber, and by turning it one-fourth around from time to time will prevent anyrritation to exposed membrane from suction.

This cap may be used on any kind of a plate for artificial teeth, Whether vulcanite or metal, and on any port thereof upon which it may be necessary to be used. It will also be seen that this vacuum causes the plate to adhere with great tenacity; and, as from its shape, it is impossible for the mucous membrane or gum to iill it, the traction of this cavity is constant.

Having thus described my invention, what I claim as ne, and desire to secure by Lett-ers Patent, is-

The movable pivoted cap, lying within a circular recess in the top ofthe plate, substantially as described.

DR. GEORGE MORRISON.

Witnesses:

JOHN MORRISON,

M. V. JONES. (46) 

